"Becoming California, a series that brings the California Gold Rush alive with the people who lived it."

The Gold is Gone but the Chemicals Linger On

by Don Baumgart

When this area's search for gold moved from panning in the streams to hard rock gold mining, a process began that would leave poisons behind for more than a century, lying around the area like rusting discarded tools.

At the old Lava Cap Mine near Grass Valley arsenic has been found in the soil and water, causing the site to be designated as Nevada County's only Superfund environmental cleanup site.

The Lava Cap Mine began producing in 1861 and was worked on and off until 1943, when it closed for good. During its lifetime it was consolidated with Banner Mine and the Central Mine. The mining complex originally was a major silver producer, delivering 310,000 ounces a year.

In the 1930s production at the mine switched to gold, employing 310 men to labor underground.

Ore at the mine contained natural arsenic, and at times tailings, the leftover crushed rock from which gold ore has been extracted, were piled four to seven feet high along Little Clipper Creek. Added to the cyanide used to separate gold from the crushed ore, these chemicals have now become a grim legacy of the Gold Rush.

In the mid 1990s the U.S. Environmental Protection Agency conducted soil tests that showed elevated levels of arsenic at the old mine site. The contamination came from a rotting log dam holding tailings. The wooden dam had leaked arsenic into Little Clipper Creek.

A couple of years after the test, the top of the dam gave way during a severe winter storm. Some 10,000 cubic yards of arsenic-laden tailings went into the creek and Nevada County went on the EPA books as a Superfund site with a cleanup cost estimated by the agency at more than $13 million.

The effort would have to move 8,000 truckloads of tailings. Next on the EPA agenda woill be conducting groundwater tests to see how far the arsenic and cyanide have spread.

Arsenic in uncovered tailings, says the EPA, can turn to dust and become airborne. The agency describes the stuff as both highly toxic and highly mobile.

Of four residences on the old Lava Cap Mine site, two have been evacuated. The other two probably can be restored by major earth removal.

Until relatively recent times in America, rivers and waterways were thought to be the ideal dumping ground for industrial waste. Factories had pipelines to the river banks in the eastern United States and in the West what didn't glitter was tossed aside to be dealt with by future generations.

Perhaps the first wakeup call seen across the nation was when the pollutant-laden Cayahoga River running through Cleveland, caught fire. The city manufactures car parts and steel. Cleveland companies also manufacture electronics, plastics, and chemicals. Waste products were, like at the Lava Cap Mine, just tossed aside...into the Cayahoga.

The EPA was established to deal with industrial wastes, among other problems, but few thought the agency would be brought to the gold fields to deal with problems caused by miners long gone. Following on the heels of the EPA cleanup in Cleveland, one of this country's leading industrial centers, the agency is now engaged in taking out the 100-year-old mining remains that could threaten water and health in Nevada County.

Like ghosts haunting old mines, the chemicals liberated from the rock and other potions used to free up the yellow stuff have become problems that still stalk the gold fields. The cost to remove them from the Lava Cap Mine will be at least $2 million more than the value of the gold and silver produced in the mine's heyday.